There is an image reading apparatus of the so-called flat bed type, which reads a document placed on a glass plate fixed to a document placement table with a record surface of the document set downward and includes an image reading unit (image scanner device) configured to scan the document and arranged in a lower portion of the glass plate.
In such an image reading apparatus, it is necessary to place a document in a proper position with respect to the glass plate (image scanner device) in order to correctly recognize a size of the document and read the document. Therefore, a positioning member for guiding a position of the document is arranged in the periphery of the glass plate. The positioning member is generally disposed in a state of slightly upward protruding beyond the glass plate and the side of the document is abutted on the positioning member to perform positioning.
In order to improve operability of positioning, for example, in JP-A-2004-144832, a mark portion for guiding a position to place a document is printed or inscribed on a surface of a positioning member and in addition, a mark portion for guiding a placement position is formed on a glass plate. Plural kinds of mark portions are disposed for documents with different sizes, so that a user can align correctly the document of each size.
However, in the case of the mark portion as shown in JP-A-2004-144832, since the placement is not always performed in sufficiently bright environment, it is difficult to find the mark portion when the periphery is dark and the document cannot be aligned speedily.
On the other hand, JP-A-2002-214977 discloses an image reading apparatus including an arranging light emission device in a positioning member. In the image reading apparatus, when a document is aligned with a glass plate, reference positions (for example, a back side reference for aligning with the corners of the back side of the glass plate, a center reference for aligning with the center, or a front reference for aligning with the corners of the front side) vary depending on models. As a result of that, for example, when a document is aligned by a center reference or a front reference in spite of an apparatus of a back side reference, trouble in which most of the document cannot be read is caused.
Therefore, in JP-A-2002-214977, a reference lamp is disposed as the light emission device in the vicinity of a reference position in the positioning member so that a user can recognize its reference position without making a mistake. Concretely, for example, in an image reading apparatus of a back side reference, when a cover is opened, the reference lamp disposed in the positioning member in the vicinity of a back side reference position lights roundly (see FIG. 2 of JP-A-2002-214977). Consequently, the user can speedily recognize that the apparatus is the apparatus of the back side reference and can place the document on the glass plate without mistaking the reference position.